So I've been going to the gym the past few months and doing a slightly modified version of the beginner full body thing in the OP. So far it's been working out well, but there are some hiccups.
First off, and just can't do pulls ups. I can do maybe five before I am completely spent. I think a lot of this has to do with the fact that I am slightly overweight (220lbs 6'2") and simply don't currently have the strength to support my weight. Is the only alternative I have to use the assisted pull up machine? Will the lat pulldown machine help me get up the strength to start doing actual pull ups? I can do about 150lbs on a lat pulldown. I have been working at it as a potential way to get up to the strength to pull ups and it has been progressing ok.
Second, I am just not confident yet in my strength to do a power clean. A lot of it is because I have never done them and the explosive aspect seems very intimidating and I am afraid I won't get it right. I suppose I should just start with the bar and slowly add weight and go from there. Is there anything that will help prepare me for the explosive aspect, or should I just start from really low weight and go from there?
The third problem is actually related to the second problem. I have been experiencing pain and discomfort in my right knee for a few years now. I went to the doctor and he asked when I experienced the discomfort and at the time I hadn't been doing much more than jogging as exercise and I told him I experienced no pain while exercising. He diagnosed it as spinal stenosis after fooling with my knee and bending/putting pressure on it. Well, now that I have started actual weight training I have realized that I do indeed experience a lot of pain during certain exercises. Squats, leg press, and leg extensions. I am worried about the jumping aspect of powercleans in relation to this discomfort. Should I just avoid them altogether until I get it looked at, or is it not as bad on the knees as it looks?
I have modified my squats so that I don't go quite as far down into the squat and it has eliminated almost all of the pain in my knee. I do not jog/run much anymore and do almost all of my cardio on the rowing machines. I don't really want to stop because I don't want to lose the gains I have made the past few months. Either way I will probably be going to the doctor early next month to get some things looked at.
Edit:
I should add that as I have been getting stronger, my knee has bothered me less. It hurts the worst when I squat with my legs perpendicular to the floor, or doing leg extensions (which I have basically just cut out entirely until I get it looked at).